Paper-making apparatus



July 12, 1932. Q L cRolX PAPER MAKING APPARATUS Filed Nov. 28, 1950 I NVEN TOR.

ATTORNEY.

Patented July 12, 1932 UNITED STATES FREDERICK LA CROIX, OF AGAWAM,MASSACHUSETTS PAPER-MAKING APPARATUS Application filed November 28,1930. Serial No. 498,620;

This invention relates to paper-making apparatus and is directedmoreparticularly to coverings for dandy rolls and the like.

The principal object of the invention is the provision of a covering ofnovel form for dandy rolls and the like, whereby it is possible toproduce new and novel watermarking effects.

In the detailed description of the invention hereinafter contained, thenovel features will be described in connection with coverings for dandyrolls, which for con venience will be called web-marking elements, butit will be understood that the invention may be practised in connectionwith coverings for a cylinder of a papenmaking machine or other makingelements on which a web of paper may be formed.

Various novel features of the invention and 73 the advantages thereofwill be more fully hereinafter explained in connection with theaccompanying drawing which shows the features of the invention in ageneral way and in the form at present preferred.

In the drawing:

Fig. 1 is a plan view of a portion of a marking element embodying thenovel features of the invention.

Fig. 2 is a sectional view on the line 22 of Fig. 1, and

Figs. 3 and 4 are plan views of a portion of a paper sheet as it appearswhen marked by the marking element of the invention.

Referring now to the drawing in detail the I invention will be morefully described.

In describing the invention reference will be made to a paper-makingelement, and there is shown in the drawing a section of a markingelement or cover 2 for a dandy roll.

1 Such a covering is known as a laid covering.

This covering comprises as shown a plurality of parallel barslpreferably of wire, which are secured together at intervals by ytransversely arranged wires 6. These wires 'J are arranged in thewell-known manner to interlock with the bars and hold them together andprovide a unitary covering memher.

In the ordinary practise these bars are of relatively stnf spring-likewire so that the cover is more or less still and non-yieldable.According to this invention the bars t are made from bendable andrelatively soft wire, such as soft drawn copper or the like, or thewires may be heat treated to make themsoft and bendable.

It is common practisewith such laid coverings to rotate the dandy rollso that it bears on the wet web of paper. The bars serve to displace orshift fibers in the web so that in the finished paper there appears amultiplicity of parallel dark and light lines alternately arranged. Thisis called a laid finish, and is one well known in the paper industry.The relatively dark and light lines are caused by relatively thick andthin: portions of the paper.

Such a laid finish is monotonous and heretofore there has been no way ofbreaking the monotony except that in some'cases patches of metal havebeen soldered on to the mark ing element. These when pressed by theelement into the wet web ofv paper create a design or a markingcorresponding to the. shapeof themarking element. The marking appearingof course, as a thinner. portion of the paper, like any other watermark.

According to this invention it. is desired to provide the paper withdesigns which are new in general. appearance. This is accomplishedaccording to the invention by identing a designin the marking elementformed bythebars. According to the preferred. form of the invention Ioffset the bars transversely tothe plane of the-element.

To'accomplish this I employ a design member in the form of the design itis desired to impart to the paper. This is placed on the marking elementor the marking element may be placed on the design element. In eitherevent the marking element is: pressed into the bars so'that the bars areolfset as at 3 in Fig. 2 to conform to-the shape of the design element.7

In the case shown in Fig. 1 the design member' isin the form of acrescent and: may be a piece of metal out to the shape desired, With themarking element placed thereover the element: is pressed upon: orstruckwith a rubber hammer, for instance, which forces the bendable rodsdownwardly around the design element so that together the bars areoffset to provide a depression conforming to the shape of the designelement, which in this case is a crescent. Since the bars are relativelysoft they are readily oifset and the element has a depression on oneside and a raised portion on the other.

Various designs may be used and in the manner described the bars may beoflsetso that they may be provided with depressions on one side of theelement and raised portions on the other side corresponding to the shapeof the design element. Of course a design or designs may be repeated asoften as desired throughout a marking element.

lVith the marking element thus being offset with a design, the dandyroll covered with the element bears on a'relatively wet paper Web andshifts the fibers of the web so that the paper is marked not only tohave the parallel light and dark streaks or lines, but will have thedesign of the depression associated therewith, as is indicated in Fig.3,

i which shows a piece of paper wherein there appears light and darklines 10 and 12 and a design 1a. Y

If the element is placed on the dandy roll so that the designdepressions are uppermost I the web will show the design as being darkeror thicker as in Fig. 8. If the element'has raised portions uppermostthe web will have the designs appearing as thinner or lighter withrespect to the main body. i

As stated marking elements for making laid paper have been formed frombars which are relatively stifl, such as hard drawn brass wires and thelike and it is the intention that such bars produce light and darkstreaks or lines which are substantially uniform in width and spacing toprovide an eflect which may be said to be symmetrical or regular.

The effects produced by my novel marking member may be such that'thelight and dark lines may be non-uniform in width and not in parallelismwith one another. This nonuniform and non-parallel arrangement will haveassociated with it the design as in Fig. 4. Altogether there is produceda new and pleasing effect not possible by means of the prior artapparatus. This is accomplished by shifting or bending the bars out ofparallelism as they are offset to produce the design depression andbeing bendable or relatively soft they bend readily. As shown in Fig. 4,the light and dark lines 16 and 18 are non-uniform and non-parallel andthe design 20 is associated therewith.

Various designs of course may be employed and arranged as may be desiredso that very many and beautiful effects may be created by means of themarking element which is rovided with depressions by oifsetting the arsof theelement. A

What I now desire to claim and secure by Letters Patent of the UnitedStates is:

1. A paper-marking element of the class described comprising incombination, a plurality of spaced rods of relatively soft annealedmaterial secured together at spaced points throughout their length,adjacent rods being offset from the plane of the main body thereof inthe form of a design to provide a depression and a raised portion onopposite sides of the element.

2. A paper-marking element of the class described comprising incombination, a plurality of spaced rods of relatively soft annealedmaterial secured together at spaced points throughout their length,adjacent rods being offset from the plane of the main body thereof inthe form of a design to form a depression and a raised portion onopposite sides thereof, the said rods being bent irregularly throughouttheir length so as to be non-parallel relative to one another, so as toform in wet paper contacted by the element'a series of irregular,alternate light and dark non-parallel lines having a design superposedthereon.

In testimony whereof I afliX my signature.

FREDERICK LA CROIX.

